Elliott has good speed, and he can get up to max velocity quickly, but....he doesn't have great speed like a Bo Jackson, Herschel Walker, Jamaal Charles, Chris Johnson, O.J.Simpson, Eric erson, Gale Sayers. Not as fast as Tony Dorsett.
Let's say he was faster in 2014/2015, how about 10.65? Jamaal Charles ran a 10.18 at Texas, Reggie Bush ran a 10.4ish in HS, O.J.Simpson ran a 9.4 yards, that's about a 10.35ish meters. Tony Dorsett ran a 9.5 yards, so 10.45ish.
But.....Elliotts ability to burst, to hit MV quickly gives this illusion of great speed, and as a RB that really is more important than 100m jets.